inet: Remove unused sk_sndmsg_* from UFO

UFO doesn't really use the sk_sndmsg_* parameters so touching
them is pointless.  It can't use them anyway since the whole
point of UFO is to use the original pages without copying.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>